Go down and check coupons out. Remember to check price history if it is available. Let’s see what best price is ATM.
Aliexpress
There’re some similar (or not) items on Aliexpress
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
2PCS * 3.7V 1350mAh Li-ion Battery with 2 in1 USB Charger Kit For Hawkeye Firefly 7S 8S 8SE X Action Camera S009R | $23.19 | – |
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Compatible with Hawkeye Firefly 8S, 3.85V 1200mAh
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($16.89): BGJON8
2. ($16.89): BGRCParts8
3. ($16.89): BGMatt2022
4. ($16.89): BGToys8
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): f62884, Parts8, 2019SPEDM, bgssaff9, BGBCFPV, BGBCBG10, 502C6B, BGOTC21, BGBFAFF2019, BGCITYADS2019, 2020CNY, BGVDay10%off, BGTT10, bGhOnEy10, BGFPVS10, BGSS10%SW, BGRC902, BGAFF10OFF, BG11SHOP, BGDAVIS, BGGAL8, Tabby20, BG1efeb0, 8Couponsde, MVC8SPRING, 8BGwbg2204, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BG8RCToy, BGJUNEGSG9, BGRCT10, TTSUMMER8, Cuponation9
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Hawkeye Firefly 8S S009R Battery is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).